While much evidence exists to support the positive relationship between high performing structures and processes, with improved population level health, little is known about the type of support by the delivery system, particularly health plans, necessary to achieve a high functioning health service system. The proposed research will examine the comparative effectiveness of two different PCMH strategies, including different payment and facilitated support interventions, utilized by two different regional health plans, on improvement in outcomes - cost, quality and experience in pilot practices. The Health Service System model provides a conceptual framework for this evaluation project. The proposed project is novel in that it includes two different interventions in multiple, diverse practices, each with comparison practices to control for temporal and geographic trends over time. This proposal most directly addresses the Institute of Medicine priority topic, "Compare the effectiveness of different quality improvement strategies in disease prevention, acute care, chronic disease care, and rehabilitation services for diverse populations of children and adults." PUBLIC HEALTH RELEVANCE: While much evidence exists to support the positive relationship between high performing structures and processes, with improved population level health, little is known about the type of support by the delivery system, particularly health plans, necessary to achieve a high functioning health service system. The proposed research will examine the comparative effectiveness of two PCMH strategies, including different payment and facilitated support interventions, utilized by two different regional health plans, on improvement in outcomes - cost, quality and experience in pilot practices. The Health Service System model provides a conceptual framework for this evaluation project.